Financial Instruments (Commodity Risk Management) (Details) (EUR €) In Millions, unless otherwise specified	Mar. 31, 2012	Sep. 30, 2011
EUAs [Member]
Derivative [Line Items]
Notional amount of commodity risk derivatives	€ 1	€ 1
CERs [Member]
Derivative [Line Items]
Notional amount of commodity risk derivatives	€ 1	€ 1

Aggregate notional amount of price risk derivatives, which relates to the monetary amount specified in the price risk derivative instruments. Excludes notional amounts on derivatives expressed in nonmonetary units.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1B

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6935481&loc=SL5579245-113959

Name:	us-gaap_NotionalAmountOfPriceRiskDerivatives
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant